feat: enhance code highlighting with flourite

Integrate flourite for improved language detection in code blocks, replacing manual detection logic. This enhances accuracy and supports a broader range of languages for syntax highlighting. Additionally, streamline CSS inclusion for code highlighting by importing directly from the package, reducing reliance on external CDN.

src/layouts/base.astro

@@ -57,10 +57,6 @@ const FOOTER_INJECT = getEnv(import.meta.env, Astro, 'FOOTER_INJECT')
       title={channel?.title}
       href={origin + '/rss.xml'}
     />
-    <link
-       href="https://cdnjs.cloudflare.com/ajax/libs/prism-themes/1.9.0/prism-atom-dark.min.css" 
-       rel="stylesheet"
-    />
     <style is:inline>
       @view-transition {
         navigation: auto; /* enabled */